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Battery Charger Question

Battery Charger Question

Posted: Oct 26, 2017 8:26 am

by ohiocaver

I have a 2-cell battery charger for my 18650s (Zebralight). Do these chargers work in series or something (I'm obviously not an EE)? Often I'll have one completely drained battery and the other only partly discharged -maybe an hour's use. It seems that, depending on which slot I put the two batteries, the charger will turn green almost at once, maybe 5 minutes - telling me the good battery got topped off but I doubt the spent one can be recharged that fast. If I switch the battery positions, the red charging light remains on for 45 minutes or whatever...which would appear to say that both batteries are topped off. Is this common? Do I need to mark a full/empty on my charger? Is it okay to recharge a drained and a nearly-full battery at the same time?This, btw, is why I like to standardize on AAs - I understand them! Thanks.

Re: Battery Charger Question

Posted: Oct 28, 2017 1:29 pm

by captnemo

I'm afraid I don't have a zebralight so cannot answer your question for certain. I do have 4 dive lights and three caving lights that use 18650 batteries and I have found charger behavior / quality varies considerably. Unfortunately the demand for cheap unprotected cells for use in vapes has only worsened/added confusion to the situation. I managed to find a 4 cell charger/holder on amazon that can be used to charge a cellphone / tablet when away from home, it charges each cell independently so you can put one, two etc in at a time and it shows you the current charge state of each. So far I've been very happy with it, it was under twenty bucks. I believe good chargers are going to behave this way for any lithium cells. i.e. monitor their charge independently but not all have a clear indicator of this and there are so many cheap vape chargers out there that you do need to be careful using off brand chargers.This is not the one I purchased https://smile.amazon.com/10400mAh-External-Battery-Charger-included/dp/B012CN6Q7I/ref=sr_1_3?ie=UTF8&qid=1509215124&sr=8-3&keywords=18650+cell+phone+chargerbut it looks almost identical so I imagine there are a few out there using the same design.

Re: Battery Charger Question

Posted: Oct 28, 2017 5:39 pm

by chac

I agree completely with captnemo. Choose a charger that will recharge each 18650 battery in its individual charging position as needed. There is often a "refresh" button at each battery position on many good chargers. That starts a new basic charging regimen. The CandlePower forum reviews 18650 chargers. There are good and not so good chargers. I cave with Spark, Zebra and ArmyTek single-battery lamps. I have had more problems with faulty lamps (control chips) than batteries. Some sketchy chargers are out there due to the "vape" business as captnemo mentions.

Aside from the third lamp you carry, take along a spare 18650 battery in a "waterproof" case (Amazon sells them) when you cave. They weigh nothing and if your partner's lamp fails due to a battery problem, you can solve the problem.

Re: Battery Charger Question

Posted: Oct 29, 2017 4:12 pm

by ohiocaver

Thanks to both ... I'll be ordering a new charger with individual cell chargers. And I never even considered the vape question. If your battery flicks out while you're puffing, it's inconvenient. If you find out battery is shot when you're underground, you're toast.